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Archive - Oct 12, 2020

Genomic Study Reveals Evolutionary Secrets of Banyan Fig Tree’s Aerial Roots and Specific Wasp Pollinator

The banyan fig tree Ficus microcarpa (photo) is famous for its aerial roots, which sprout from branches and eventually reach the soil. The tree also has a unique relationship with a wasp that has coevolved with it and is the only insect that can pollinate it. In a new study, researchers identify regions in the banyan fig's genome that promote the development of its unusual aerial roots and enhance its ability to signal its wasp pollinator. The study, published online on October 8, 2020 in the journal Cell, also identifies a sex-determining region in a related fig tree, Ficus hispida. Unlike F. microcarpa, which produces aerial roots and bears male and female flowers on the same tree, F. hispida produces distinct male and female trees and no aerial roots. The Cell article is titled “Genomes of the Banyan Tree and Pollinator Wasp Provide Insights into Fig-Wasp Coevolution.” Understanding the evolutionary history of Ficus species and their wasp pollinators is important because their ability to produce large fruits in a variety of habitats makes them a keystone species in most tropical forests, said Ray Ming, PhD, a Plant Biology Professor at the University of Illinois, Urbana-Champaign who led the study with Jin Chen, PhD, of the Chinese Academy of Sciences. Figs are known to sustain at least 1,200 bird and mammal species. Fig trees were among the earliest domesticated crops and appear as sacred symbols in Hinduism, Buddhism, and other spiritual traditions. The relationship between figs and wasps also presents an intriguing scientific challenge. The body shapes and sizes of the wasps correspond exactly to those of the fig fruits, and each species of fig produces a unique perfume to attract its specific wasp pollinator. To better understand these evolutionary developments, Dr.

Blocking Alternative Complement Pathway with Factor D Inhibitor May Halt COVID-19 Infection & Prevent Severe Organ Damage, Johns Hopkins Study Suggests

While the world waits eagerly for a safe and effective vaccine to prevent infections from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing the COVID-19 pandemic, researchers also are focusing on better understanding how SARS-CoV-2 attacks the body in the search for other means of stopping its devastating impact. The key to one possibility--blocking a protein that enables the virus to turn the immune system against healthy cells--has been identified in a recent study by a team of Johns Hopkins Medicine researchers. Based on their findings, the researchers believe that inhibiting the protein, known as factor D (image), also will curtail the potentially deadly inflammatory reactions that many patients have to the virus. Making the discovery even more exciting is the fact that there may already be drugs in development and testing for other diseases that can do the required blocking. The study was published online on September 2, 2020, in Blood. The open-access article is titled “Direct Activation of the Alternative Complement Pathway by SARS-CoV-2 Spike Proteins Is Blocked by Factor D Inhibition.” Scientists already know that spike proteins on the surface of the SARS-CoV-2 virus are the means by which it attaches to cells targeted for infection. To do this, the spikes first grab hold of heparan sulfate, a large, complex sugar molecule found on the surfaces of cells in the lungs, blood vessels, and smooth muscle making up most organs. Facilitated by its initial binding with heparan sulfate, SARS-CoV-2 then uses another cell-surface component, the protein known as angiotensin-converting enzyme 2 (ACE2), as its doorway into the attacked cell. The Johns Hopkins Medicine team discovered that when SARS-CoV-2 ties up heparan sulfate, it prevents factor H from using the sugar molecule to bind with cells.